Pipe mold



Feb. 23, 1932. D. B. DlMlcK 1,846,997

v PIPE MOLD riginal Filed oct. 23, 1929 lnvenfor Patented Feb. 23, 1932 UNITso stares DANIEL BAKER DIMICK,VF BIRMINGHAM, ALABAMA k:PIPE MOLD Original application filed October 23, 1929, Serial No. 401,767. Divided and this application ii1ed December 19, 1930. Serial No. 503,578.

The present invention relates to vimprovements in pipe molds, and is a division of my copending application Ser. No. 401,767, filed October 23, 1929, entitled Method and appa- ...5 ratus for castingpipe.

' An object of the invention is to provide an improved pipe mold whereby cast iron, culvert pipe having locking keys for effecting a lock joint between adjacent pipe sections may be cast expeditiously, at the same time 'involving a high degree of accuracy and uniformity in the size, thickness and other dimensions of the pipe and keys.k f

Another object of the invention is to provide an improved pipe mold in which a pipe having a thickness of wall may be produced with a minimum expenditure of labor and power, and in which the capacity of the plant will be materially increased.

A further object of the'inventio-n is to provide an improved pipe mold, in which the operations of ramming, molding, finishing and pouring are all accomplished in one position of the mold, that is, with the bell up.

lVith the foregoing and other objects in view, the invention will be more fully described hereinafter and will be more particularly pointed out in the claims appended hereto.y

In the drawings, wherein like symbols refer to like or corresponding parts through the several views,

Figure l is a vertical center section of the kcomplete' flask mold with stripping plates in place ready for the pattern to be withdrawn, and

Figure 2 is a vertical sectional view of the completed mold ready for bottom pouring of the pipe.

Referring more particularly to the draw-- ings, designates a casting stool, which constitutes the bottom of the flask and the mold. The casting stool may be provided with one or more pockets 2lto center and hold the 45 bottom pour gate cores, when used. The casting stool 2O is also drilled to receive the cheek centering pins 22 and the arbor centering pins 23. The cheek is designated at 24 and constitutes the outside retaining wall of the k5f) liask, the same being machined to the length of the pipe mold desired. The cheek 24 is provided with a perforated flange 25 at its lower portion to receive `the centering pins 22. These pins retain the cheek in proper concentric'relation with the stool 20. The 5 core arbor is designated at 26 and is provided with the perforated ange 27 to receivethe centering pins 23. This arbor 26 is machined to the length of the straight bore of the pipe mold desired.

rlhe pins 23 are located concentrically with the center of the flask. The core arbor 26 be provided with wings 28 to support and hold the molding sand in place in the core of the finished mold.

The pattern is shown at 29. This pattern is constructed for the straight bore ofthe desired pipe and also for the outside of the bell of said pipe. rThe top portion of the pattern 29 is extended to receive means forwithdrawing the pattern from the flask mold, and for this purpose, openings 30 are provided in the upper extended portion of the pattern.

At 3l is shown cast iron spigot end taper locking key chills, the inside surface of each being formed to the radius of the outside of the'pattern. A cavity 32 is provided in the inner surface of each chill having the size and forni of the desired spigot end taper'locking key for its respective pipe pattern. The chills 3l are received into recesses provided in the sectional cast iron spigot key chill rings 34, which are securely attached to the casting stool in such manner and in such relation to the center ofthe flask as to hold the inside surfaces of the spigot key chills, and thereby the pattern 29,` concentric with the flask.

The parts' are such as to hold the spigot key chills 3l in place against the pressure of the moldingsa'nd after the withdrawal of the pattern, and for this purpose, the upper edges of the chills 3l are sloped, as indicated at 36, whereby to deflect the pressure of the sand outwardly.

In Figure l, 37 designates the outer stripping plate'machined in bore to lthe outside diameter of the top or enlarged bell end of the pattern 29. The inside stripping plate is represented at 38.- This inside stripping is 100 CTI machined on its outer diameter' to the bore of the pattern. A weighted or massive cast iron centerin Y plug 39 rests upon the arbor 26 within t e inner stripping ring or plate38.

The engaging surfaces of the plug 39 and stripping plate 38 are properly machined and theYY outside surface of the lug 39 is preferably tapered as shown. 'lphe outside stripping plate 37 is held in place by the use of clamps 40 in a well known manner. The tempered molding sand rammed in place between the Yattern 29 and cheek 24 is represented at 4 and the sand between the attern 29 and the arbor 26 is shown at 42. A ter the -witlrdtawalcf the pattern, a mold cavity 43 is left in theY sand, as shown in Figure 2.

i As shown in Figure 2,7744 designatesra pouring gate cavity made'in therammed molding sand as a restricted path for the molten iron to travelfrom the pour basin 45 to-thecasting stool core gate.Y

Asshown in F igurer2, the lower end of this pouring gate cavity 44 communicates with one or more horizontal gate cavities 46 and Similar connecting vertical cavities 47, which latter communicate with the lower enfd of the mold cavity 43. A runner box is shown inY Fi e 2 as being in place on the flask.

e runner box 48 may be a combination of cast iron and steel of such form as to support. the tempered molding sand 49, when' rammed to the shape and size desired to make a combined bell core and pour basin. YAt .are shown the impressions made in the bell Acore by the bell locking key patterns, leaving cavities of the size andin the positions desited for bell locking keys. Y

use 0f the device, the castingstool 20is carefully bored so that the openings for thefpins 22 are equi-distant from the center. In, likemanner, the inner pins'23 for the arbor are also equi-distant from the center of th casting stool. Y

Care is also taken in the formation of the a4 to machine it. so that a will be cfmneentrc and properly receive the pins 22, vwhereby such cheek 24 is accurately concentric with the casting stool. The core arbor 26 isalso machined carefully and ext-ends up to the bell line. Care must be taken to have the arbor 26 concentric both with the casting stool 20 and with the fiask or Vcheek 24. The wings 28 on the core arbor 23 are for the purpose of supporting the sand inthe Gore and the arbor is preferably made with the barrel tapered, and with the small end down to facilitate removal from the pipe. The sectionalspigot key chill rings 34 are bolted to the upper surface of the casting stool 20, and are so centered that, when the y'spigot key chills 31 are in place, the inside curved surfaces of the chills 31 form sections offoeirele concentric with respect to the vcraexis of theY casting stool and of the same radius as that of the outside of the pattern 29.

YYThe pockets inthe rings 34 will restrain theE the beveled upper portions ofthe chills 31,

they are made to press closely against the pattern 29. i

The cavities 32 in the chills form'mold cavities of the exact size and "shape of the spigot locking keys desired.

The casting stool, cheek, core arbor, chill rings and chills, together with the centering pins make up a complete flask. lVhen the completed asks are assembled, the cheeks 24 are clamped to the casting stools 2() for ease of handling by overhead cranes.

Vshen the flask is being kassembled for a size and weight pipe requiring bottom pouring of the metal, dry sand gate cores 52, as shown in Figure 2, are placed in the pockets 21 in the casting stool 20, said cores being so placed that the smali gate cavities 47, through which the metal is to enter the atteru cavity, are concentric with and will be covered bv the pattern during ramming of the sand. l/Vhen the flask is assembled for a size and weight of pipe requiring top pouring, these pore gate cores 52 are omitted, and the casting stool pockets 2l filled level full of sand, or a casting stool is used of the same form but with the gate core pockets eliminated.

The molding operation is started by placing a complete flask on the table of a molding machine. The pattern 29 is then lowered into the flask, being centered with respect to the flask and molding machine by the spigot key chills 31 and they in turn by the vchill rings 34 fastened to the casting stool.

It has been found that certain sizes and Weights of pipe may be made better when the tempered. molding sand is rammed on a jarring machine or jolter. In this method, with the flask and pattern in place, together with the pattern for the gate 44 shown in Figure 2, when the mold is to be bottom poured tempered molding sand is shoveled or spouted into the space between the cheek and pattern and into the space between the core arbor and pattern. The conventional jarring machine or jolter is so made that when compressed air is ailowed to flow into the machine, the piston and table attached thereto, together with the flask and sand, are caused to be jarred or jolted and the sand thereby rammed. f

Certain other sizes and Weights are better molded by the sand slinger method. In this method, the flask and pattern are placed, as before, in 'a centered position on a turntable.

The table is caused to rotate and the Hask and pattern are caused to rotate therewith and between the core arbor and pattern with such force that the sand is rammed to the density desired.

Upon completion of the above filling and ramming of the iiask mold, the sand outside the pattern is leveled even with the top of the cheek 24 and the sand inside the pattern is leveled even with the top of the core arbor 26.

As the pattern 29 is machined with inside and outside diameters concentric, and as the inside stripping plate 38 is machined with inside and outside diameters concentric7 the largest outside diameter of the centering plug 39 must now be concentric with the outside diameter of the pattern 29.

The next operation is to remove the pattern from the fiask mold.

lWith the appliance shown in the original application, the core and inside stripping plate 38 are held down while the pattern Q9 is withdrawn a sufficient distance to break the static friction between the bore of the pattern and the sand of the core.

After the pattern 29 is completely removed from the mold, the stripping plates 37 and 38 are likewise removed. The centering plug 39 is, however, left in place. Being of massive design, the centering plug 39 will not move during any careful handling of the mold and will remain central with the pattern impression by virtue of its mass alone. The completed fiask mold is removed from the molding machine and placed on the pouring floor ready to receive the combined bell core and pour basin 48.

rl"his bell core and pour basin are formed separately from the flask in a machine shown and described in said parent application. The runner box 48 is internally bored to fit the largest outside diameter of the centering plug 39. rlempered sand 49 is rammed in the runner box, the sand taking the shape of the bell core desired. s

After its formation, this combination bell core and pour basin is now ready to be placed on the completed flask mold. In Figure 2, the combined bell Core and pour basin is shown as placed on the complete flask mold, being centralized as it is lowered down by the centering plug 39, thus completing a bell mold of even thickness. The completed pipe mold appears in Figure 2 and is ready for pouring.

After pouring, the runner box 48 is removed from the mold and returned tothe machine on which it is formed; the core arbor 26 is remo-ved ready to be cleaned and replaced on any casting stool 20; the cheek 24 is removed ready to be cleaned and replaced on any casting stool 20, the pipe casting is removed for cleaning and finishing, the spigot key chills and chill ring and casting stool are cleaned, and the molding sand retempered ready for the making of another mold.

It will be noted that in all description of parts and through the explanation of the mold cavity, and, therefore, all parts of the completed pipe, are concentric, and that the pipe, as cast, is even in thickness throughout.

It will be obvious that various changes in the construction, combination and arrangement of parts could be made, which could be used without departing from the spirit of my invention, and I do not mean tolimit the invention to such details, except as particularly pointed out in the claims. v

Having thus described my invention, what I claim and desire to secure by Letters Patent of the United States is 1. A pipe mold comprising a casting stool, a core arbor on said stool, a cheek on the stool concentric of the arbor, molded sand between the core arbor and cheek having a mold cavity therein with spigot end down and bell end up, a heavy centering plug mounted on the core arbor, and a runner box containing a combined bell core and pour basin mounted on the core and cheek and centered by said centering plug.

2. A pipe mold comprising a flask containing sand with a pipe mold cavity therein having the bell end up, a centering plug mounted on the flask, and a runner box containing a combined bell core and pour basin mounted on the flask concentrically of the mold cavity and centered by said centering plug.

3. A pipe mold comprising a flask containing sand with a pipe cavity therein having the bell end up and the spigot down, a removable runner box containing a bell core and pour basin fitted upon said flask, and a tapered centering ring supported by the flask and for centering the bell core with respect to the mold cavity.

4. A pipe mold comprising a flask including a core arbor, a massive tapering centering plug supported loosely on said arbor, and a runner box containing a bell core removably mounted on the flask and slidable downwardly over the tapering surface of the plug whereby to guide the bell core concentrically with respect to the pipe cavity in the flask.

5. A pipe mold comprising a flask for containing the 'material in which the pipe cavity is formed with bell up, said flask including a corel arbor, centering means loosely mounted on said core arbor, and a runner box containing a bell core removably fitted on the fiask and over said centering means, whereby to accurately locate the bell core concentrically with respect to the bell portion of the mold cavity.

' DANIEL BAKER DIMICK. 

